1. Field of the Invention
The present invention relates to a piston for an internal combustion engine, having a piston head that has a circumferential cooling channel as well as a combustion bowl having a circumferential bowl wall that makes a transition into a piston crown by way of a bowl edge region. The combustion bowl is formed at least in part by a piston base body, and the bowl wall is formed at least in part from an insert. The present invention furthermore relates to a method for the production of such a piston.
2. The Prior Art
A piston of this type is described in German Patent Application No. DE 30 32 671 A1. It has a piston base body made of a flow-pressed steel and an insert welded or soldered to the piston base body, made of a highly heat-resistant material. The piston base body is provided with a combustion bowl in the region of the piston head, which bowl is delimited by a circumferential bowl wall that makes a transition into the piston crown by way of the bowl edge region. The piston base body and the insert form a circumferential cooling channel.
The bowl wall and, in particular, the bowl edge region are subject to particularly great mechanical and thermal stresses during operation, which stresses lead to material fatigue over the course of time, which in turn can cause cracks to form. For this reason, inserts structured in numerous ways have been proposed, in order to reduce or neutralize the stresses that act on the bowl edge region. Because of the further development of engine technology, these suggestions are no longer able to keep pace with the increased mechanical and thermal stresses on pistons during engine operation.